Circular knitting machine of the opposed needle cylinder type and method of knitting thereon



F. E. DEA NS ET'AL CIRCULAR KNITTING MACHINE OF. THE OPPOSED Aug. 3, 1954 2,685,186,

NEEDLE CYLINDER TYPE AND METHOD 4 0F KNITTING THEREON I 7 Filed Apr 25, 19 2Sheets-Sheet 1 Inventors: EDWARD DEANS AND qwmss FREDERIK MANGER u..e

A 8- 3, 1954 F. E. DEANS EI'AL 2,685,186

CIRCULAR KNITTING, MACHINE OF THE OPPOSED NEEDLE CYLINDER TYPE AND METHOD 0F KNITTING THEREON Filed April 25, 1952 2 Sheets-Sheet 2 Inventors: ARD ms Aim RLEs FREDERIK MANG-ER Patented Aug. 3, 1954 CIRCULAR KNITTING MACHINE OF THE OP- POSED NEEDLE CYLINDER TYPE AND METHOD OF KNITTING THEREON Frederick Edward Deans and Charles Frederick Manger, Leicester, England, assignors to The Bentley Engineering Company Limited, Leicester, England Application April 25, 1952, Serial No. 284,282

Claims priority, application Great Britain April 26, 1951 Claims. (Cl. 66-14) This invention concerns circular, independentneedle, knitting machines of the type having two opposed or superimposed needle cylinders equipped with double ended needles capable of transfer from one cylinder to the other to change the rib structure or pattern, said machines being constructed and arranged to knit fabric by rotary motion between the cylinders and their needle-actuating cams and also to knit a pouch by oscillatory motion (or, as it is commonly termed, reciprocation) between said cylinders and cams. Such machines are herein referred to as being of the opposed needle cylinder type, and the invention is especially concerned with machines of this type wherein the needle cylinders rotate or reciprocate at the appropriate times, although it is applicable to machines wherein the needle cylinders are stationary and the cams rotate or oscillate about the cylinder axis. The chief object of the invention is to effect certain improvements which facilitate the production of pouches on machines of th said type and especially to facilitate the production of heel and toe pouches on machines of this type which are organised to knit seamless stockings or socks.

When knitting a pouch by reciprocation on a machine of the above type it is usual to knit on a part of the circle of needles only (these needles being in the lower, or plain, cylinder) and to raise those needles which are not knitting to a high inactive loop-holding level. As the needles which are knitting rise again after drawing their loops the sinkers move inwards and hold the yarn in their hooks and after the last needle which knits has drawn its loop the yarn should lie freely outside the raised inactive needles and above the sinkers but there is a tendency for the sinkers to continue to take the yarn and to draw it between the inactive needles, making a wave-like formation of it. When the machine reverses the yarn must be straightened out again and pulled back through the feeder. To do this the takeup has to put more tension on the yarn than should be necessary and the action of the sinkers and take-up together have a serious effect on the yarn, often causing it to break. When two or more yarns are being knitted together it sometimes happens that one of the yarns is engaged by the sinkers and drawn into a wave like formation and the other is not. The take-up cannot then straighten out the wavy yarn and faulty fabric is the inevitable result. This difficulty does not usually occur to any marked extent on single cylinder machines because the yarn feeder can be placed at such a height that the lie of the yarn from the feeder to the needles is at a sufficiently steep angle to allow the ingoing sinker to pass under the yarn as it lies outside the first two idle needles. In the case of a double cylinder machine, however, it is not possible for the yarn feeder to be quite as high in relation to the draw edge for the plain needles because during circular rib-knitting the yarn has to be fed to rib needles also, below the rib draw edge, and the two draw edges (for rib and plain stitches) are desirably as close together as possible. However, in spite of the relatively low position of the feeder, the angle of the yarn as it lies from the feeder to the plain needl drawing a loop is, in most cases, sufficiently steep that were each sinker (when its associated needle is active) to move inwards at the time that the associated needle is drawing a loop (or even a little later) then, during pouch knitting, the sinker following the first idle needle would be able to pass under the yarn without kinking it. Unfortunatel the sinkers do not normally make their inward movement until considerably later than the time just mentioned and when the point is reached at which they do make this movement the angle of the lie of the yarn is so much reduced that, if knitting by reciprocation is taking place, the sinker following the first idle needle can no longer pass under the yarn but engages it and kinks it between the needles; succeeding sinkers do likewise.

The reason for the late inward movement of the sinkers in a rib machine is that it is very desirable that the rib loops as Well as the plain loops should be held by the sinkers, particularly when there are a number of adjacent rib loops; consequently after the rib needles have drawn their loops they travel in a retracted attitude through a sufiicient distance to ensure that the following needles draw their loops entirely from the yarn supply and not partly from a previously drawn loop, and then they are lowered until the rib loop are low enough to be engaged by the sinkers which then move into engage them. This fixes the earliest point at which the sinkers can make their inward movement and the upthrow cam for the plain needles has to be placed in the appropriate relation to this. This upthrow cam raises the plain needles (in the bottom cylinder) from their lowest level, thereabouts, to a position a little above the draw edge, thereby causing the attitude ,of the loops to change from the substantially vertical to the substantially horizontal.

Owing to the substantially horizontal disposition of the loops at the time the sinkers move in, the parts with which the sinkers engage (viz. those loop parts which are commonly known as sinker loops) are disposed some distance inwards of the needle circle. It follows that a considerable inward movement of the sinkers is necessary to bring the sinker loops or throat into engagement with these sinker loops. Therefore, while for the reasons already set out it is not possible to give the sinkers this entire movement at an earlier point, there is the possibility of giving the sinkers a partial inward movement of suificient amplitude and at a sufiiciently early point to cause the yarn extending from the last active needle to the feeder to lie over the top of the sinker following the first idle needle, with the result that the yarn is not kinked, by the sinkers, between the idle needles.

The invention therefore provides a circular knitting machine of the opposed needle cylinder type, having holding-down sinkers and means for advancing the sinkers inwards in two stages, viz. a first stage of such an amplitude and at such a time that the yarn extending between the last active needle and the feeder during reciprocatory knitting is not kinked by the sinker follow ing the first inactive loop-holding needle, and a second stage at which the sinkers associated with activ needles move inwards to engage the sinker loops.

Specifically, the amplitude of the first stage is such as to bring the point of each sinker nib inwards of a line which, at the level of said point, joins the outer surfaces of the needles on either side of that sinker. These needles therefore mask the point of the nib and prevent the idle yarn (being that length of yarn which, during reciprocation, extends between the feeder and the last active needle) getting into the throat of the sinker, with the result that the idle yarn is disposed above the sinker nibs. The second stage takes place at the time of and in effect completes what is normally the sinker knockover movement. The plain needles continue to rise after this second stage as they do after the normal knocking-over advance.

While the difficulties that the aforesaid two stage movement seeks to overcome or minimise only occur during reciprocation, it is preferred for the sake of simplicity that the two stages shall be employed even during rotary knitting (although the cam or the like that produces the first stage may be movable to an inoperable position for rotary knitting, so that a normal sinker advancing cam produces the entire sinker advance). That is to say, the first stage takes place just after the plain needles have drawn their loops over the draw edg of the sinkers, so that when the sinkers do move in their nibs engage over drawn loops, and the second stage takes place after the rib needles have been lowered to bring their loops to a sufficiently low level to permit the sinkers to engage the sinker loops of said loops.

The foregoing and other features of the invention set out in the appended claims are incorporated in the machine and method of operation which will now be described in detail with reference to th accompanying drawings in which Figure 1 is a developed view, looking on the outside of the needle circle, showing the disposition of the needles at a stage where the last of the heel-half needles have drawn loops of yarn and the first of the raised instep-half needles have passed the feeding point prior to the needle cylinders making their first reciprocation in knitting the heel;

Figure 2 is a plan view on a larger scale of the parts shown in Figure 1;

Figure 3 is a section taken on the line A--A in Figure 2, while Figures 4, 5, and 6 are sections taken on lines 13-3, 0-0, and D-D in Figure 2;

Figure 7 is a developed view of the sinker cams, looking on the outside of the cam ring, in which the lines AA, B-B, C-C, and D-D correspond to the similarly lettered section in Figure 2.

Figure 3 shows sufiicient of the machine to permit it to be identified as a machine of the type specified, attention being directed to the bottom or plain cylinder I, the top or rib cylinder 2, their respective cam boxes 3, 4, the double ended needles 5 and the associated sliders 6, 1,

in the bottom and top cylinders respectively, the sinker ring 8, the curved sinkers 9 therein, the sinker cam ring In with its track H for th butts 12 of the sinkers, and the feeder I3 for feeding the yarn T. The sinkers have the usual hooks I4, throats l5 and draw edges l5.

Other details of the machine ar of conventional character and require no illustration or description herein.

When knitting a pouch by reciprocation on a machine of the opposed needle cylinder type it is usual to knit that pouch only on a group of the needles 5 (these needles being in the lower or plain cylinder l) and to raise those needles which are not knitting to a high inactive loop-holding level. These inactive needles are grouped by a bracket 5a in Figure 1 and are sometimes referred to as the instep-half needles. Some of the active or heel-half needles are grouped under the bracket 5b in Figure 1. As these needles 5b rise after having drawn their loops from the yarn T the sinkers 9 move inwards and hold the yarn in their hooks I5 and after th last active needle (shown at 5b at the left hand end of the group 5b in Figure 1) has drawn its loop the yarn should lie freely outside the raised inactive needles 5a and above the sinkers. However the normal path of the sinkers is shown by the chain-dotted line I! in Figure 2 and it will be seen that the sinkers normally remain in their outer position until the point [8 is reached. Thus as the sinker 9 following the extreme active needle 5?)" above mentioned makes its inward movement from the point 18 there is a tendency for this sinker to take the yarn and to draw it inwards. Subsequent sinkers associated with the inactive needles 5a do likewise and draw the yarn between the inactive needles 5a to make a wave-like formation of it. This difiiculty has already been discussed.

According to the present invention this difficulty is overcome by moving the sinkers 9 inwards in two stages for which purpose the sinker cam track I l is formed as shown in Figure 7. It will b seen that this cam track has a part Ha providing for the extreme outer position of the sinkers, an incline 1 lb providing for the first stage of inward movement and leading to a dwell part No, the second incline lid, and a final inner track lle.

Thus at a stage prior to that at which th last active needle 51) is raised by the upthrow cam 19 the sinkers are moved in by the incline Ilb. This brings them to the attitude shown in Figure 4 in which it will be seen that the tip of the sinker hook i4 is shielded by the shank of the needle 5. As a result the yarn T is laid over the.

gamma top of the sinker hook l4 and is not enclosed in the throat l5. Necessarily therefore, and notwithstanding the fiat angle at which the yarn T is fed by the feeder [3, the yarn is laid safely over the tops of the hooks of all the succeeding sinkers and the difii'culties are obviated.

This first stage in the inward movement of the sinkers does not prevent the loops newly formed by the active needles being properly drawn over the draw edges 16- of the sinkers as shown in Figure 5, for the dwell portion llc following the first stage extends until the active needles (associated with the sinkers that are travelling along said dwell portion) descend to their knock-over level.

At or about the time that the up-throw cam l9 causes the active needles to rise until their hooks are slightly above the draw edges [6 of the sinkers so that the attitude of the newly drawn loops changes from the substantially vertical attitude shown in Figure 5 to the substantially horizontal attitude shown in Figure 6, the sinkers are given the second stage of their inward movement by the incline l id. This second stage takes place at the time of and in effect completes what is normally the sinker knock-over movement. Thereafter the active needles continue to rise in the usual manner.

It will be appreciated that the operations above discussed take place in both directions of swing of the cylinder or cams as the case may be for this purpose the inclines lib and lid and the dwell part lie of the sinker track are duplicated at Ilb, Ho and Hal as shown in Fig. 7.

We claim:

1. In a circular knitting machine of the opposed needle cylinder type the combination of a needle cylinder, needles in said cylinder, means for feeding yarn to said needles, a sinker bed associated with the said cylinder, hooked sinkers mounted in said sinker bed in association with said needles so as to be movable outwardly and inwardly of the needle circle, cam means for operating said needles and sinker operating cam means for operating said sinkers, said sinker operating cam means being formed to cause preliminary inward movement of said sinkers timed to occur immediately after the loop drawing movements of the associated needles when active and to an extent to bring the points of the sinker hooks to the line of the needle circle, said sinker operating cam means being also formed to cause the sinkers to dwell after such preliminary movement and subsequently to be withdrawn to their innermost positions for completion of the knitting action.

2. In a circular knitting machine of the opposed needle cylinder type the combination of a main needle cylinder, needles in said cylinder, cam means for operating said needles to cause them to draw loops in the yarn fed to the needles, a yarn feeder for feeding yarn to said needles, a sinker bed associated with said cylinder, hooked sinkers mounted in said sinker bed for inward and outward movement with respect to the needles, and sinker operating cam means acting on said sinkers, said sinker operating cam means including a cam track formed to cause inward movement of the sinkers from their outermost positions in two distinct stages with a dwell therebetween, the first stage inward movement of each sinker being timed to occur immediately after a loop drawing movement of an associated active needle whereby yarn extending from said loop will be caused to enter the sinker hook by said first stage inward movement of the sinker, the sec- 0nd stage inward movement of each sinker being timed to occur when the associated active needle has been raised substantially to the level of the sinker hook.

3. In a circular knitting machine of the opposed needle cylinder type the combination comprising a tricked main needle cylinder, needles slidable in the cylinder tricks, needle operating cam means acting on said needles to cause loop drawing and subsequent raising movements thereof, a feeder for feeding yarn to said needles, a sinker bed associated with said main cylinder, throated sinkers mounted in said sinker bed for movement outwards and inwards of the needle circle, said sinkers having inwardly directed throats and draw edges extending inwardly from the bottoms of their throats, and sinker operating cam means acting on said sinkers to effect their outward and inward movements, said sinker operating cam means including a track formed to produce inward movement of the sinkers in two stages with a dwell therebetween and being timed to cause the first stage inward movement of each sinker to occur after commencement of the loop drawing movement of an "active adjacent needle whereby the yarn extending from such loop will engage the draw edge of the sinker during said first stage movement before being embraced in the sinker throat at the conclusion of said first stage movement, and to cause the second stage inward movement of each sinker to occur during raising movement of an active adjacent needle when the hook of such needle has reached the level of the sinker throat.

4. In a circular knitting machine of the opposed needle cylinder type the combination comprising a tricked main needle cylinder, needles mounted for movement in the tricks of said cylinder, needle operating cam means for operating said needles for loop drawing and up-throw movements; a feeder for feeding yarn to said needles, a sinker bed associated with said main cylinder, sinkers mounted in said sinker bed formovement outwardly and inwardly of the needlecircle across the line of the needles, said sinkers. having draw edges extending outwardly to inwardly directed throats, butts on the sinkers, andi sinker operating cam means to engage the buttsx on the sinkers, said sinker operating cam means providing a track for the sinker butts such that the inward movement of the sinkers is effected in two stages, namely a first stage in which the sinkers are withdrawn to a position at which upstanding needles will mask the sinker throats and a second stage in which the remainder of the inward movement of the sinkers is completed, said sinker operating cam means being timed to cause said first stage movement to occur when an associated active needle has performed sufficient of its loop drawing movement to carry the fed yarn into engagement with the draw edge of the adjacent sinker so that such yarn may readily pass into the sinker throat at the conclusion of the first stage movement, said sinker operating cam means being also timed to cause said second stage movement to occur during the up-throw movement of an associated active needle when such needle has reached the level of the sinker throats.

5. A method of operating a circular knitting machine of the opposed needle cylinder type which consists in giving the sinkers during reciprocatory knitting a two stage inward advance with a dwell between the two stages, the first stage being so timed with respect to the movements of active needles associated with the sinkers that the yarn extending from the feeder to an active needle is withdrawn by the loop forming movement of the needle across a portion of the adjacent sinker disposed inwardly beyond its throat immediately prior to inward movement of the sinker to cause the yarn to be engaged in the sinker throat, the said first stage movement being of such amplitude as to bring the mouths of the sinker throats substantially on the needle circle so as to be 10 masked by any upstanding inactive needles, and the second stage movement being so timed that the sinkers associated with active needles move in and draw the sinker loops substantially horizontally after the active needles have commenced their up-throw movement following knock-over.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,385,056 Bromley Sept. 18, 1945 2,555,870 Bristow June 5, 1951 

